Ed,
Here's what I would do.
Gold mode recovery speed setting and iron bias settings may be too high (both default to 6 in Gold 1)and unless you have highly variable ground readings at your search site, turn GB tracking OFF and do and auto (or manual) GB. Lower recovery speed to 4 or less so you can get a better signal return and this should help with depth and turn Iron Bias off to prevent your signal from being masked. If you are trying to get TID (like 1 or 2) and lowering recovery speed did not help, then you may want to bump threshold and just listen for changes in threshold. You may also want to just go with single frequency (20 or 40 KHZ) see which once gives you a better response. Crank sens as high as you can without causing chatter. Once you have adjusted the detector to be as hot and responsive as possible on your test target by adjusting the parameters I have suggested, go find that other stud.
Also, I suspect that you don't have to just do this in Gold mode. I would experiment with Park 2 with the same settings (Iron Bias is already 0 in Park 2, but lower recovery speed from 6 to 4). Use All Metal, Auto GB (not tracking), and crank the volume on the TID segment that the earring rings up in. Good luck.